Waste disposal apparatus



WASTE DISPOSAL APPARATUS Filed April 6, 1959 & i

Q 0 INVENTORS ALBERT L. HARDY gT'HOMAS T. WOODSON THE 5 R ATTORNEY 2,970,777 WASTE DISPOAL APPARATUS Albert L. Hardy, Louisville, Ky., and Thomas T. Woodson, La Canada, Califi, assignors to General Electric Company, a corporation of New York Fiied Apr. 6, 1959, Ser. No. 804,238

4 Ciaims. (Cl. 241-46) This invention relates to motor driven waste disposal apparatus of the type adapted to be connected to the drain opening of a kitchen sink, and has as its general object the provision of an improved motor sealing arrangement for such apparatus which effectively prevents water from entering the bearings of the motor and the motor itself.

Further objects and advantages of the invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention will be pointed out with particularity in the claims appended to and forming a part of this application.

Briefly stated, in one embodiment of this invention as applied to a waste disposer having a grinding chamber, a rotary plate or flywheel at the bottom thereof, an annular drainage chamber underlying the rotary plate and a motor supported below the drainage chamber, there is provided air tight sealing means in the motor forming an enclosed air space in the portion thereof occupied by the motor shaft and rotor, and an inverted cup-shaped member within the drainage chamber secured in air tight relation to the shaft. The size and shape of these parts are so proportioned that the volume of air space within the cup-shaped member is substantially greater than the volume of the enclosed air space within the motor, and thus the liquid level in the drainage chamber is prevented by air pressure from rising high enough to enter the clearance between the motor shaft and the upper motor bearing.

For a better understanding of this invention, reference may be made to the following description and the accompanying drawing in which the single figure is a fragmentary elevation view, in section, of a waste disposer embodying the present invention.

Referring to the drawing, there is shown a waste disposer having a generally cylindrical housing 1 enclosing a grinding chamber 2 at the bottom of which grinding and shredding ot waste material takes place. The upper end of housing 1 is provided with means suitable for supporting the device in the drain opening of a sink or the like, the supporting means including, for example, a flanged drain sleeve 3, a clamping ring 4 and a sealing washer 5. Such an arrangement is more fully disclosed and claimed in Patent 2,805,826, granted September 10, 1957, to Bernard J. Brezosky.

The lower end of housing 1 is provided with a flange 6 which carries mounting screws 7 for securing a motor housing 8 to the hopper so as to form an integral structure. Mounted within housing 8 is an electric motor 9 provided with a vertically extending shaft 10 to which is fixedly secured suitable rotary grinding means positioned at the bottom of chamber 2. In the illustrated embodiment of the invention the rotary grinding means comprises a Hat genearally circular plate or flywheel 11 and movable impellers 12 and 13 secured thereto. These impellers cooperate with a cylindrical shredding ring 14 tates Patent 6 ring 14 is provided with a top flange 15 which, together with the sealing ring 16 is clamped between oppositely facing ledge portions of housings l and 8. The shredding ring is provided with a plurality of shredding projections 17 on its inner surface and also a plurality of openings 18 adjacent the periphery of rotary plate 11 through which comminuted waste material and water is expelled during operation of the devise. Material expelled from the grinding chamber 2 passes into a drainage chamber 19 which is formed by an inner cylindrical wall 20, an outer cylindrical wall 21 and a bottom wall 22 all of which are integral with motor housing 8. Drainage chamber 19 is of course provided with an exit opening 23 to which may be secured a suitable drain line (not shown).

In accordance with the present invention, an inverted generally cup-shaped member 24 is secured in inverted position within drainage chamber 19 and in air tight relation to shaft 10 for rotation therewith. For example, cup-shaped member 24, rotary plate 11 and an impeller locking plate 25 may be stacked on top of the upper end of shaft 10 and fixedly secured thereto by means of a screw 26 in engagement with an axial opening in the shaft.

In addition, since rotation of these parts during operation may create splashing of the liquid within drainage chamber 19, an inverted cup-shaped member 27 is secured to shaft 10 in overlapping relation with cylindrical wall 20 to prevent splashing of liquid into the bearing structure which supports shaft 10. A stationary annular wall member 28 secured to wall 20 is also provided to confine splashing to the lower portion of cup-shaped member 24. As shown in the drawing, the bearing structure for shaft 10 includes an upper sleeve bearing 29 and a lower sleeve bearing 29a. Lubrication for the bearings is provided by a sealed oil supply system which includes an oil sump 30, a cone shaped member 31 secured to shaft 10 and arranged to function as an oil pump which forces oil up through line 32 to lower bearing 29:: and also through clearance space 33 to upper bearing 29. Oil supplied to upper bearing 29 is returned to sump 30 through an oil return line 34. A cup-shaped member 340, which rotates with shaft 10 and functions as an oil slinger, is provided to direct oil emerging from the upper end of the bearing into the return line.

The stator of motor 9 is encapsulated in a suitable plastic material 35, such as epoxy resin, and this structure is suitably secured within lower flange 36 of motor housing 8. In order to reduce the air space within motor 9 a cylindrical block of plastic material 37 is secured to housing 8 immediately above rotor 38 and this air space is further reduced by inwardly extending annular portion 39 of sealing block 40 which is secured to the motor structure at the bottom thereof. The space occupied by rotor 38 and shaft 10 is thus fully enclosed, and is sealed by an upper seal ring 41 and a lower seal ring 42. It is evident that the volume of the enclosed air space within motor 9 is quite small, and that the volume of air space within cup-shaped member 24 is substantially greater than the volume of the enclosed air space within the motor.

This air space relationship is important. since cupshaped member 24 functions as a diving bell whenever the liquid level in chamber 19 rises above the lower edge of member 24. When this accurs, the pressure of the entrapped air in the cup-shaped member and the motor increases by an amount equal to the static head of the water in the drainage and grinding chambers. Thus an equilibrium condition is established. and the maximum static liquid level is limited by air pressure. For example, if the air space within cup-shaped member 24 is three times as great as the enclosed air space within the motor,

a water head of several feet (far in excess of the maximum head that might be present in disposers installed in kitohensinlts) would be required to raise the water level even as high as annular wall 28. v i In operation, it will be understoodthat Water and waste material enter grinding chamber 2 through the top'op'em ing of housing 1, and that water is supplied continuously during grinding operations. As communition of the waste material proceeds, a mixture of such material and water is discharged into drainage chamber 19 through openings 18 and is then dischargedthrough drain opening 23. As the liquid level in drainage chamber 19 rises above the lower edge of cup-shaped member 24 the air therein and the air enclosed within motor 9 is compressed since the air cannot escapefrom this enclosed space. Thus cup-shaped member 24 performs a function similar to that of a diving bell and the liquid level is prevented from rising high enough to flood top bearing 29. Further, any splashing of the liquid within cup-shaped member 24 is: confined to the zone outside cup-shaped member 27 since the lower lip thereof is in overlapping relation with the upper end of cylindrical wall 20, and splash guard member 28 confines most splashing to the lower half of member 24. Thus it will be seen that our invention provides a fully elfective water seal for the bearings of motor 9 while eliminating conventional rotary shaft seals which tend to wear out and leak with use.

While we have shown and described a particular ernbodiment of our invention we do not desire the invention to be limited to the particular construction disclosed, and we intend by the appended claims to cover all modifications within the true spirit and scope of our invention.

What we claim is:

1. Waste disposal apparatus comprising a housing providing a grinding chamber having at its upper end an inlet opening for water and waste material, grinding means including a rotary plate at the bottom of said chamber, wall means forming an annular drainage chamber underlying said rotary plate, an electric motor supported below said drainage chamber, said motor having a housing with a rotor and a stator, the rotor having a shaft extending through said drainage chamber in driving engagement with said rotary plate, said motor housing including air tight sealing means forming an enclosed air space within the portion of the housing occupied by said rotor and shaft, and a liquid sealing means including a relatively large diameter inverted cup-shaped member within said drainage chamber secured in airtight relation to said shaft for rotation therewith to provide a large air chamber, the volume of air space Within said large air chamber being substantially greater than the volume of the enclosed air space within said motor housing, whereby water entering this chamber at the bottom acts like a large piston compressing the air in the chamber and the inverted cupshaped member functions as a diving bell to prevent water from entering the motor.

2. Waste disposal apparatus comprising a'housing providing a grinding chamber having at its upper end an inlet opening for water and waste material, grinding means including a rotary plate at the bottom of said chamber, wall means forming an annular drainage chamber underlying said rotary plate, an electric motor supported below said drainage chamber, said motor having a rotor and a shaft extending through said drainage chamber in driving engagement with said rotary plate, said motor including air tight sealing means forming an enclosed air space in the portion thereof occupied by said rotor and shaft, an inverted cup-shaped member Within said drainage cham ber secured in airtight relation to said shaft for rotation therewith, the volume of air space within said cup-shaped amid??? member being substantially greater than the volume of the enclosed air space within said motor. and a stationary splash guard formed by an annular wall secured to said wall means and positioned within said cup-shaped member in a plane generally perpendicular to the axis of said shaft, the said inverted cup-shaped member functioning as a diving bell to prevent water from entering the motor.

3. Waste disposal apparatus comprising a housing providing a grinding chamber having at its upper end an inlet opening for water and waste material, grinding means including a rotary plate at the bottom of said chamber, wall means forming an annular drainage chamber underlying said rotary plate including an upstanding generally cylindrical wall member forming the radially innermost wall of said drainage chamber, a motor supported below said drainage chamber, said motor having a rotor with ashaft extending through said drainage chamber within said cylindrical wall to be in driving engagement with said rotary plate, said motor including air tight sealing means forming an enclosed air space in the portion thereof occupied by said rotor and shaft," a first inverted cup-shaped member within said drainage" chamber secured in airtight relation to said shaft for rotation therewith, the volume of air space within said first cup-shaped member being substantially greater than the volume of the enclosed air space within said motor, and a second inverted cupshaped member positioned within said first cup-shaped member and secured for rotation therewith, said second cup-shaped member having a downwardly projecting lip arranged in close proximity to and in overlapping relation with said generally cylindrical wall member.

4; Waste disposal apparatus comprising a housing providing a grinding chamber having at its upper end an inlet opening for water and waste material, grinding means including a rotary plate at the bottom of said chamber, wall means forming an annular drainage chamber underlying said rotary plate including an upstanding generally cylindrical wall member forming the radially innermost wail of said drainage chamber, an electric motor supported below said drainage chamber, said motor having a housing with a rotor and a stator, the rotor having a shaft extending through said drainage chamber within said cylindrical wall to be in driving engagement with said rotary plate, said motor housing including air tight sealing means forming an enclosed air space in the portion thereof occupied by said rotor and shaft, a first inverted cup-shaped member within said drainage chamber secured in airtight relation to said shaft for rotation therewith, the volume of airspace within said first cupshaped member being substantially greater than the volume of the enclosed air space within said motor housing, a second inverted cup-shaped member positioned within said first cup-shaped member and secured for rotation therewith, said second cup-shaped member having a downwardly projecting lip arranged in close proximity to and in overlappingrelation with said generally cylindrical wall member, and a stationary annular wall secured to said cylindrical wall member and positioned within said first-mentioned cup-shaped member in a plane generally perpendicular to the axis of said shaft and below the second-mentioned cup-shaped member.

References Cited in the file of this patent UNITED STATES PATENTS Wilder Sept. 23, 1958 

